Preheat oven to 350 degrees. In a largemixing bowl, combine the pumpkin, butter, yogurt, cold coffee, vanilla and sugars, stirring to combine. Add the baking powder, baking soda, salt and spices, stirring well to combine. Add the eggs and beat with a wooden spoon until well combined; add flour and mix only until all the flour is incorporated into the batter. Stir in the chopped Werther’s candies (or butterscotch morsels) and turn into a 9×13-inch baking pan that has been greased and floured.
Bake for 30-35 minutes or until center springs back when touched. Cool in pan on a wire rack until completely cool, if frosting.